Determination of wheel polygonal wear limit and fatigue life of railway bogie frames considering wheel/rail excitation

This paper presents an innovative method for determining the fatigue life of railway bogie frames with track irregularities and wheel polygonal wear. This method was employed to predict wheel polygon limits to protect against bogie frame fatigue. Firstly, a comprehensive coupled vehicletrack system dynamic model was established. The developed model was validated by comparing the numerical results with field test data. Secondly, the dynamic stress characteristic of the bogie frame with different excitation forms were investigated. A methodology was proposed to compile the stress spectra of bogie frame by considering the influence of the wheel polygonal wear. This approach enabled the construction of comprehensive stress spectra by considering influences arising from both track irregularities and wheel polygonal wear. Subsequently, the stress spectra of the concerned positions on the bogie frame were developed and further used to study the influence of wheel polygonal wear amplitude on the fatigue life of the bogie frame. This facilitated the development of the maintenance limit of wheel polygonal wear from fatigue life perspective. The results suggest that the maintenance limit of wheel polygonal wear should not exceed 0.034 mm in the presence of a 24th-order wheel polygon for a typical high-speed train.